The present invention relates to call signaling services performed in a mobile telecommunications network, and more particularly to methods and systems for providing such services in a network routing element.
A typical wireless or cellular telecommunications network, generally indicated by the numeral 100, is illustrated in FIG. 1. Such networks typically employ a number of functional elements or entities including but not limited to: a telecommunication terminal or telephone handset 102, a base station (BS) 104 and associated base station controller (BSC) 106, a mobile switching center (MSC) 108, a gateway MSC (GMSC) 110, a home location register (HLR) 112, a visitor location register (VLR) 114, an equipment identity register (EIR) 116, and an authentication center (AuC) 118. These network elements are communicatively coupled via a variety of communication link types, which in turn may employ a variety of communication protocols. are communicatively coupled via a variety of communication link types, which in turn may employ a variety of communication protocols.
Of particular relevance to the integrated routing node of the present invention are the switching and database type network nodes, mentioned above, that facilitate much of the intelligent network services that are characteristic of modern wireless telecommunication networks. A brief discussion of each of their functions follows.
Mobile switching center (MSC) 108 is the functional entity that represents an automatic packet switching system within a wireless communication network. When such a packet switching system is implemented so as to serve as the interface for user traffic between the cellular network and other public switched networks, the corresponding node is often referred to as a Gateway MSC or GMSC. In general, MSC 108 provides basic switching functionality and coordinates the establishment of calls between wireless end users. The MSC is directly responsible for transmission facilities management, mobility management, and call processing functions. The MSC is typically in direct contact with both base stations (BSs) and with voice and signaling related network nodes. The MSC incorporates switching functions, mobile application functions, and other service logic functions.
Home location register (HLR) 112 is the functional entity that represents the primary database repository of subscriber information used to provide control and intelligence in wireless networks. The term register denotes control and processing center functions as well as the database functions. The HLR is managed by the wireless service provider and represents the xe2x80x9chomexe2x80x9d database for subscribers who have subscribed to service in a particular geographic area. The HLR contains a record for each xe2x80x9chomexe2x80x9d subscriber that includes location information, subscriber status, subscribed features, and directory numbers. Supplementary services or features that are provided to a subscriber are ultimately controlled by an HLR. An HLR incorporates database functions, mobile application functions, as well as other service logic functions, and may serve one or more MSCs.
Visitor location register (VLR) 114 is the functional entity that represents the local database, control, and processing functions that maintain temporary records associated with individual network subscribers. A VLR is managed by a wireless service provider and represents a temporary database of xe2x80x9cvisitingxe2x80x9d subscribers that have roamed outside of their home service area. A xe2x80x9croamingxe2x80x9d visitor can be a mobile subscriber being served by one of many systems serviced by their wireless service provider or network operator. A roaming visitor can also be a mobile subscriber who is roaming in a non-home, or visited, service area (i.e., a network operated by different service provider). A VLR contains subscriber location, status, and service information that is derived from a roaming subscriber""s HLR. A local network MSC accesses a VLR to retrieve information for the handling of calls to and from visiting subscribers. A VLR incorporates database functions, mobile application functions, as well as other service logic functions and may serve one or more MSCs.
Equipment identity register (EIR) 116 is the functional entity that represents the database repository for mobile equipment related information. EIRs are typically used to store information related to electronic serial numbers (ESNs) associated with mobile terminals (e.g., handsets). Such an EIR database implementation could be used to prevent stolen or unauthorized mobile terminals from being activated and used within a wireless network fraudulently.
Authentication center (AuC) 118 is the functional entity that represents the authentication functions used to verify and validate a mobile subscriber""s identity. The AuC manages and processes authentication information related to a particular mobile subscriber. Typically, this information consists of encryption and authentication keys as well as complex mathematical algorithms used to prevent fraudulent or unauthorized use of the wireless network. An AuC incorporates database functions used for the authentication keys and authentication algorithm functions.
As indicated in FIG. 1, the above described wireless network elements function together to provide the intelligent network services typically associated with modern wireless telecommunication networks. As such, inter communication between these network elements is a very important issue, and is facilitated at least in part by signaling communication links. In Europe, the signaling protocols for mobile communications are defined in the Global System for Mobile Communications (GSM) standards. Both IS-41 and GSM standards include a mobile application part (MAP) protocol component for performing mobile call signaling functions. Accordingly, as used herein, the term xe2x80x9cMAP messagexe2x80x9d is intended to refer to both IS-41 and GSM MAP messages.
Signaling in a wireless or cellular network is employed to implement a number of call processing operations. The term xe2x80x9ccall processingxe2x80x9d encompasses a wide variety of functions that establish, maintain, and tear down calls to and from mobile subscribers (where a call is defined as a temporary communication between end users for the purpose of exchanging information). Mobile calls include a sequence of events that allocate and assign the resources and signaling channels required to establish a communication connection, with the first event in the sequence typically being call establishment. In general terms, the act of call establishment or call setup in a wireless communications network includes a set of functions that arrange for the connection of cellular calls.
With particular regard to wireless calls, the nature of use dictates that there are essentially two types of calls, mobile-originated and mobile-terminated calls. Mobile-originated calls are those that are placed or originate from a mobile station, while mobile-terminated calls are defined as those calls that are made to a mobile station. Mobile-originated calls are established from a mobile subscriber (MS) (i.e., the calling party) to a telecommunications termination point (i.e., the called party) that can be located in either a wired or wireless telecommunications network. Mobile-terminated calls are established from either a wired or wireless xe2x80x9ccalling partyxe2x80x9d telecommunications terminal to a xe2x80x9ccalled partyxe2x80x9d mobile subscriber.
In addition to providing the infrastructure for basic call setup and teardown operations as mentioned above, wireless signaling is also responsible for providing general mobility management services. Such services enable the communications network to maintain location and mobile subscriber status information so that end users can make and receive such mobile-originated and mobile-terminated calls while moving or roaming from place to place. It should be noted that a mobile-to-mobile call is usually treated as the combination of a mobile-originated call scenario and a mobile-terminated call scenario.
Both mobile-originated and mobile-terminated calls typically make use of the extensive infrastructure and routing facilities that exist within the public switched telephone network (PSTN) to create the connections between the calling and called parties. However, call signaling/connection through direct trunking between mobile switching centers (MSCs) that are in close proximity is sometimes employed for mobile-to-mobile calls. Such local mesh networking architectures are typically used in high traffic areas where there are many mobile subscribers and many mobile-to-mobile calls.
The establishment of a cellular call may involve both IS-41 and traditional Signaling System 7 (SS7) ISDN User Part (ISUP) call control signaling to properly connect the call between parties. IS-41 call processing signaling is used to obtain the location, status, routing, and any special call treatment information about a mobile subscriber to properly complete mobile-terminated calls. It is also used to obtain call treatment and routing information for mobile-originated calls. This signaling is provided by the IS-41 intersystem operations. With regard to intersystem handoff, IS-41 signaling is also used to control the inter-MSC trunks. A more detailed discussion of IS-41 signaling can be found in Mobile Telecommunications Networking With IS-41 by Michael D. Gallagher and Randall A. Snyder, McGraw-Hill Publishing 1997. Traditional call control signaling is used to establish trunks and propagate the call, as well as information about the call, from the calling party to the called party. Call control signaling is generally provided by the out-of-band SS7 ISUP protocol, but can be provided via an in-band multi frequency (MF) type signaling protocol. Depending upon the particular network implementation and service required, signaling can be provided by GSM, IS-41, SS7 ISUP or combination of thereof.
Shown in FIG. 2 is an example of a typical wireless signaling progression associated with registration of a mobile station or handset in a wireless communication network 150. In wireless telecommunication networks, mobile station registration is the process by which a mobile subscriber (MS) is identified to the network. Registration indicates the location and status of the MS to the responsible network functional entities. More specifically, the network entities primarily responsible for maintaining MS location and status information are the VLR and HLR. As indicated in FIG. 2, in many cases, VLR functionality is incorporated directly within an MSC switching node.
With regard to the signaling message flows during the process of MS registration shown in FIG. 2, a mobile subscriber handset 152 sends a signal, requesting a call setup, to a local base station 154. The base station unit 154, with the assistance of base station controller 156, signals the combined MSCNLR entity 158, thereby conveying the call request. The combined MSCNLR 158 then formulates an IS-41 signaling message (e.g., a LocationRequest Invoke message), which is intended to obtain information about the location of the called party, and transmits this message to the called party mobile subscriber""s HLR 160. HLR 160 receives the information request message and subsequently responds toMSC/VLR 158 with a new message (e.g., a LocationRequest Return Result message) which contains at least a portion of the information necessary to complete the requested call.
It should be appreciated that the example shown in FIG. 2 is only one of the many signaling related communication operations that are required to facilitate the broad range of functions and user services provided by modern wireless telecommunication networks.
Shown in FIG. 3 is a simplified wireless network 170 that includes a first MSC node 174, a second MSC node 176, a third MSC node 178, and a plurality of wireless service related nodes (e.g., HLRs, EIRs, AuCs). More particularly, network 170 includes a mated pair of HLR nodes, generally indicated by the numeral 180. The MSC and wireless service nodes are typically interconnected via an intermediate SS7 network using an IS-41 communication protocol. It will be appreciated that in the network architecture shown, each of the MSC nodes 174, 176, 178 is connected to the mobile service nodes via a Signal Transfer Point (STP) 182.
Referring to FIG. 4, with regard to the communication of signaling messages between a MSC and an mobile service node, it will be appreciated that an IS-41 mobile signaling message sent from an MSC to a mobile service node typically includes a Message Transport Part (MTP) level 1 component 186, an MTP level 2 component 188, an MTP level 3 component 190, a Signaling Connection Control Part (SCCP) component 192, a Transaction Capabilities Application Part (TCAP) component 194, and an IS-41 Mobile Application Part (MAP) component 196, as generally indicated in FIG. 4. It will be appreciated from the diagram presented in FIG. 4 that an STP deployed in a mobile communications network typically uses only information contained in MTP levels 186 through 190 of a mobile services signaling message to perform the routing necessary to deliver the signaling message to a target destination. In some cases, where global title translation type routing is required, an STP may utilize information contained in the SCCP portion 192 of the signaling packet to make a routing decision. In any event, utilization or processing of signaling message information content above the SCCP layer 192 does not occur at the STP.
Such network implementations involving the use of signal transfer points are commonly deployed for a variety of reasons. One major reason involves the significant cost savings associated with running a single dedicated SS7 link from each MSC to one STP node, as opposed to requiring a dedicated SS7 link from each MSC to every other MSC and to every mobile service node (i.e., mesh configuration). Those skilled in the art of telecommunication networks will appreciate that this concept is fundamental to the nature and purpose of the SS7 network, and consequently the motivation and merit of such SS7 network connectivity will not be discussed in detail herein. In general, within the context of the network configurations described above, wireless network operators have discovered that fewer and shorter distance communication links tend to be less expensive to deploy and subsequently maintain.
It will also be appreciated by those skilled in the art of wireless telecommunication networking that as the volume of mobile subscribers increases and the range of services offered to these subscribers increases, the transaction rate capacity of the wireless network database services entities described above will also be required to increase correspondingly.
Therefore, what is needed is a system and method of deploying a wireless telecommunication network database services entities, such as an HLR, VLR, EIR, or AuC, that is easily scaleable, provides high message processing transaction rates, and minimizes communication link requirements.
According to one aspect, the present invention includes a communications network element that is capable of providing the message routing functionality of a Signal Transfer Point (STP) as well as the functionality typically provided by wireless service nodes. Such wireless or mobile service nodes include, but are not limited to, a Home Location Register, a Visitor Location Register (VLR), an Authentication Center (AuC), an Equipment Identity Register (EIR), a World Wide Web (WWW) translation server, and a Short Message Service (SMS) center. The mobile services routing node includes a communication module capable of transmitting and receiving data packets over a network. A discrimination process receives incoming data packets and subsequently directs certain packets to a mobile services database manager. The mobile services database manager facilitates access to an appropriately provisioned mobile service database process based on information contained within the data packets. Signaling message packets received by the mobile services routing node may result in the updating or modification of data contained within one or more of the mobile service database processes. Furthermore, mobile service database process may generate new messages, in response to the receipt of certain mobile service related signaling messages.
Accordingly, it is an object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with a Home Location Register (HLR) node.
It is another object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with a Visitor Location Register (VLR) node.
It is another object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with an Equipment Identity Register (EIR) node.
It is another object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with an Authentication Center (AuC) node.
It is another object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with a Short Message Service (SMS) node.
It is another object of the present invention to provide an STP-like routing node that is capable of performing the mobile service functions typically associated with a World Wide Web (WWW) user ID/Mobile Identification Number (MIN) translation service node.